Installation guide

INSTALLATIONSECTION 3
C4
C8
Wall bracket Assembly
C7
Hose Assembly
Cold Water
Inlet of
Water Heater
C2 Check Valve
Assembly
C3 Expansion Valve
(a)
Balanced Cold Water
take-off (if required)
C1 Combined Pressure Reducing
Valve / Strainer
Cold Water Inlet
NB. Tees, elbows, stop valves and
pipework not supplied.
OPTIONAL PARTS
C6 Tundish
C5
Temperature/
Pressure
Relief Valve
The Wall Mounting
Assembly C7 & C8
is available as an
optional extra
Fig. 11
Unvented Systems should be fitted by an Approved Installer.
The water heater can be used on unvented hot water storage systems with the addition of an
Unvented Systems Kit, part number B290 available from Andrews Water Heaters.
See Parts List on page 56. The wall bracket assembly (shown below) is available as an
optional extra (AWH Part No - B173).
When used in an unvented system, the Andrews Water Heater will supply hot water at a
pressure of 3.5bar (51lbf/in
2
), provided that this pressure is available at the mains feed. During
conditions of no-flow, system pressure may rise to a maximum of 6 bar (87Ibf/in
2
) whilst the
burner is operating. When testing the system, it is recommended that a maximum test
pressure of 8.6 bar (125lbf/in
2
) is employed.
The expansion vessel C4 supplied is suitable for the stored volume of the water heater.
FOR SYSTEMS WITH LARGER PIPE VOLUMES OR ADDITIONAL STORAGE, EXPANSION
VESSELS WITH MORE CAPACITY ARE AVAILABLE - CONTACT ANDREW'S SALES OFFICE
FOR FURTHER DETAILS.
The combined temperature and pressure relief valve C5, must be installed into the horizontal
1" dia. male tapping. A 1" dia. socket (not supplied) is required as the T&P valve is also a
male fitting. The discharge pipe from items C3 and C5 must be connected into tundish C6.
When assembling items C1 and C2, ensure that the flow arrows marked on the components
are pointing in the direction of flow, i.e. towards the water heater.
The cold water for services may be drawn from the 22mm compression port on item C2(a).
The water pressure at this point will be similar to that available at the hot water outlet of the
water heater. If port (a) is not used, it should be sealed with the blanking plug supplied.
WATER
CONNECTIONS
UNVENTED
SYSTEMS
34